JP2004184761A

JP2004184761A - Polygon mirror, optical deflector of polygon mirror, machining tool for polygon mirror, and method and device of manufacturing polygon mirror

Info

Publication number: JP2004184761A
Application number: JP2002352752A
Authority: JP
Inventors: Bunto Ando; 文刀安藤; Hideki Konno; 秀樹今野
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2002-12-04
Filing date: 2002-12-04
Publication date: 2004-07-02

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polygon mirror which is easily machined and useful for preventing an image defect generated by the abnormality of the shape of the mirror surface of the polygon mirror, an optical deflector using the polygon mirror, a machining tool for the polygon mirror, a method of manufacturing the polygon mirror and the device of manufacturing the polygon mirror. <P>SOLUTION: The machining tool 48 of the polygon mirror is lightly force-fitted into the inside of a cylindrical part 3, and the square column part 5 is pressed and held by the bottom face 63a of the circumferential wall part 63 of an upper holding fixture 44. Side faces 100b are mirror finished to be flat in the state that individual side faces 100b of the polygon mirror 100 are elastically deformed into a concave shape by being pressed and held. The side faces 100b become convex when the pressing force is released, and become flat due to a deformation given by a centrifugal force when rotationally driven at high speed. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、複写機、プリンタ、ファクシミリ等の画像形成装置や画像読取装置に関連するポリゴンミラー、ポリゴンミラーの光偏向装置、ポリゴンミラーの加工治具、ポリゴンミラーの製造方法及びポリゴンミラーの製造装置に関する。
【０００２】
【従来の技術】
従来、画像形成装置や画像読取装置に用いられるポリゴンミラー（回転多面鏡）として、例えば図１１に示すようなものが知られている。このポリゴンミラー１は、回転軸２及びマグネット４とともに回転子６を構成し、画像形成装置等においては図示を略す固定子に対して回転軸２を中心に回転する。ポリゴンミラー１は、例えばアルミニウム合金を鍛造して得られる金属加工品（図１２参照）を後述のように鏡面加工して製造され、平面視正多角形（ここでは正六角形）の盤状の正角柱部５と、正角柱部５の下面側に形成された円筒状の円筒部３と、正角柱部５の上面側中央に形成された突出部１ａとを有する。
突出部１ａの中央で上記正六角形の重心位置には嵌合孔８が設けられ、回転軸２はその嵌合孔８に嵌合されてポリゴンミラー１に取り付けられる。また、マグネット４はその外径が円筒部３の内径と略同径の円筒状を呈し、円筒部３の内側に回転軸２と同心となるように固着される。そして、円筒部３内に装着されたマグネット４に対向する位置に所定距離離間させて巻線コイル（図示せず）を配置し、この部分がモータとして機能するように構成される。
正角柱部５の六つの側面１ｂは鏡面加工された平滑な光反射面（ミラー面）であり、その鏡面加工は図１２に示す加工装置１０により行われている。この加工装置１０は、鏡面加工前のポリゴンミラー１を保持する保持装置１１と、保持装置１１により保持された鏡面加工前のポリゴンミラー１の側面１ｂを研削する研削工具１２とを備える。研削工具１２は、工具回転軸を中心に鉛直面内で回転する回転円盤２４にバイト２２が取り付けられて構成されている。
【０００３】
保持装置１１は、角度割出し盤２６と、治具ベース２５と、固定シャフト２８と、保持治具２１と、回転防止部材１９と、拡縮部３０と、回転操作部２０と、基準面当接部３４とを有する。角度割出し盤２６は水平面内で装置回転軸を中心に回転可能であり、その上面には凸部３５が形成されている。治具ベース２５の下部にはその凸部３５に係合する凹部３６が設けられ、この凹部３６が凸部３５に係合することによって治具ベース２５が角度割出し盤２６上に位置決め固定されている。
治具ベース２５には上方に向けて延びる突堤部２７が形成されているとともに、その中央で凹部３６の上方には治具ベース２５を上下方向に貫通する貫通孔３７が形成されている。固定シャフト２８はその貫通孔３７に嵌合されて治具ベース２５の上方に突出し、筒状を呈する保持治具２１の下部内側に嵌合している。保持治具２１の下部には鍔部２３が形成され、この鍔部２３の下面２３ａが突堤部２７の上面２７ａに当接することにより保持治具２１が上下方向に位置決めされている。
また、固定シャフト２８と保持治具２１との嵌合により両者の軸心が装置回転軸に一致して、保持治具２１が水平方向に位置決めされている。回転防止部材１９は、その保持治具２１が治具ベース２５上で回転することを防止し、いわゆる「回り止め」の役割を果たしている。
【０００４】
拡縮部３０は、図１３に拡大して示すように、保持治具２１の上部内側に設けられている。この拡縮部３０は全体としては筒状を呈するが、実際にはそれを周方向に等分割して得る形状の複数の構成部材が集合してなり、各構成部材の間隔が変化することによって筒径Ｄ１が拡大又は縮小するようになっている。拡縮部３０の上部外周側には、上方に向かって連続的に径が拡大するテーパー面３０ａが形成されている。保持治具２１の上部内周側には、そのテーパー面３０ａに接するようにテーパー面２１ａが形成されている。拡縮部３０の上部内周側は後述のように回転軸２をチャックするチャック穴３３となっており、このチャック穴３３の周壁には回転軸２の損傷を防止するためのゴム等からなる保護部材３８が設けられている。
回転操作部２０は、保持治具２１の外周面に形成されたネジ溝２９ａに螺合され、このネジ溝２９ａに沿って回転しながら上下に移動するようになっている。保持治具２１にはネジ溝２９ａの下方に位置するように鉛直方向に延びる長孔３９、３９が形成され、拡縮部３０の下部には長孔３９の幅（図１２及び図１３において紙面垂直方向の幅）と略同寸の径を有するピン３１が水平方向に延びるように固定され、このピン３１の両端部３１ａ、３１ａが長孔３９、３９を通って保持治具２１の外側に突出している。また、拡縮部３０は図示を略すバネ部材により上方に付勢され、この付勢力によりピン３１の両端部３１ａ、３１ａが回転操作部２０に下方から当接している。
回転操作部２０を回転させてこれを下方に移動させると、上記付勢力に抗してピン３１が下方に移動して拡縮部３０が下降する。このとき、テーパー面３０ａがテーパー面２１ａに対して摺接しながら下方に移動するので、拡縮部３０を構成する上記構成部材の間隔は徐々に狭くなり、対向する構成部材間の距離であるチャック穴３３の径（筒径Ｄ１）は縮小する。
一方、回転操作部２０を回転させてこれを上方に移動させると、上記付勢力によりピン３１が回転操作部２０に追従して拡縮部３０が上昇する。このとき、テーパー面３０ａがテーパー面２１ａに対して摺接しながら上方に移動するので、拡縮部３０を構成する上記構成部材の間隔は徐々に広くなり、チャック穴３３の径は拡大する。
【０００５】
基準面当接部３４は、回転操作部２０の上方に位置するようにネジ溝２９ａに螺合されている。この基準面当接部３４は上面３４ａが水平となるように微細に取付調整され、その上面３４ａには加工前のポリゴンミラー１の加工基準面である円筒部３の底面３ａが当接される。なお、基準面当接部３４には周方向に沿って複数の側穴４０が設けられているが、この側穴４０には図示を略す棒状部材が挿入可能であり、回転軸２が拡縮部３０にチャックされたが締付力が弱いときには、その棒状部材により締付力を高めることができるようになっている。
この加工装置１０により加工前のポリゴンミラー１を鏡面加工するには、まず、図１１においてポリゴンミラー１の嵌合孔８及び円筒部３に回転軸２及びマグネット４を取り付けた後、図１３において回転操作部２０を操作してその回転軸２をチャックする。このとき、円筒部３の底面３ａを基準面当接部３４の上面３４ａに当接させてポリゴンミラー１の姿勢を水平にし、回転軸２の軸心を装置回転軸に一致させる。
続いて、その装置回転軸を中心に角度割出し盤２６を回転させて、加工前のポリゴンミラー１の側面１ｂを研削工具１２の回転円盤２４に正対させる。そして、側面１ｂと回転円盤２４との距離関係を微調整した後に回転円盤２４を回転させ、両者を相対的に移動させつつ側面１ｂをバイト２２により研削して側面１ｂを鏡面加工する。
以降、回転軸２をチャックしたまま角度割出し盤２６を回転させて全ての側面１ｂを順次回転円盤２４に正対させ、各側面１ｂを上記同様の手順で鏡面加工し、加工後、回転操作部２０を操作してチャックを解放することによりポリゴンミラー１を含む回転子６が得られる。
尚、上記したような従来技術であるポリゴンミラーや光偏向装置などが提案されている（例えば、特許文献１、２参照）。特許文献１のポリゴンミラーでは、補強リブを設けることで回転時におけるミラー反射面の変形を抑制しており、特許文献２の光偏向装置では、回転多面鏡の厚さが径方向外側に向かって徐々に増すようなテーパー形状にすることで回転駆動時の反射面形状の変形を低減させている。
しかしながら、特許文献１においては、補強リブを新たに設けるために部品の大型化を招いたり、ポリゴンミラー本体と補強リブを一体形成するために加工が複雑になるなどの問題がある。また、特許文献２においては、テーパー形状にしなくてはならないので、加工に手間がかかるという問題がある。
【特許文献１】実開平６−２３３２号公報
【特許文献２】特開２００１−４９４６公報
【０００６】
【発明が解決しようとする課題】
ところで、近年、画像形成装置等については高速化、高性能化（高画質化）の要求が厳しく、これに用いられるポリゴンミラーについても高速回転可能で高精度であることが求められている（例えばポリゴンミラーのミラー面の平面度品質（面精度）に関して言えば、要求精度が４λ／５（λ＝０．６３３μｍ）からλ／５に引き上げられている。）。
ポリゴンミラーの高速化はポリゴンミラーの形状精度にも影響を及ぼす。例えば、３００００ｒｐｍ程度の高速回転では、遠心力によって、ポリゴンミラーの鏡面端部が膨らみ、ミラー面が凹形状となる。高速化が進むほど鏡面端部の膨らみ量は大きくなる。ミラー面が凹形状となると、ビーム径が太くなったり、焦点距離の位置ズレ等の要求性能を満足することができなくなり、回転ムラ（ジッター）が生じ、縦線ゆらぎ等の画像不良となる。したがって、遠心力の影響を受けるミラー面形状は高速回転駆動時において所望の平面度となることが重要である。
このような要求に対しては、例えば、実開平６−２３３２号公報のポリゴンミラーや特開２００１−４９４６公報の光偏向装置などが提案されている。実開平６−２３３２号公報のポリゴンミラーでは、補強リブを設けることで回転時におけるミラー反射面の変形を抑制しており、特開２００１−４９４６公報の光偏向装置では、回転多面鏡の厚さが径方向外側に向かって徐々に増すようなテーパー形状にすることで回転駆動時の反射面形状の変形を低減させている。
しかしながら、実開平６−２３３２号公報では、補強リブを新たに設けるために部品の大型化を招いたり、ポリゴンミラー本体と補強リブを一体形成するために加工が複雑になるなどの問題がある。また、特開２００１−４９４６公報については、テーパー形状にしなくてはならないので、加工に手間がかかるという問題がある。
そこで、本発明は、上述の問題点を解決するためになされたもので、加工が簡単で、ポリゴンミラーのミラー面の形状異常によって発生する画像不良の防止に役立つポリゴンミラー、ポリゴンミラーを用いた光偏向装置、ポリゴンミラーの加工治具、ポリゴンミラーの製造方法及びポリゴンミラーの製造装置を提供することを目的とする。
【０００７】
【課題を解決するための手段】
上述の問題点を解決するために、請求項１記載の発明では、側面をミラー面とした正角柱部と、前記正角柱部の底面に形成した円筒部とを備えたポリゴンミラーにおいて、前記ミラー面は回転駆動時の遠心力によって変形して平坦になるようにしたポリゴンミラーを最も主要な特徴とする。
請求項２記載の発明では、前記円筒部内に配した治具からの押圧力によって前記側面を凹状に変形させた状態で鏡面加工することにより、前記治具を外したときに前記側面が凸状となるようにしたポリゴンミラーを主要な特徴とする。
請求項３記載の発明では、前記正角柱部と前記円筒部を挟んで押圧保持した状態で前記側面の鏡面加工をしたポリゴンミラーを主要な特徴とする。
請求項４記載の発明では、側面をミラー面とした正角柱部と、前記正角柱部の底面に形成した円筒部とで構成されたポリゴンミラーを有し、前記ポリゴンミラーの前記ミラー面は回転駆動時の遠心力によって変形して平坦になるようにしたポリゴンミラーの光偏向装置を主要な特徴とする。
請求項５記載の発明では、前記円筒部内に配した治具からの押圧力によって前記側面を凹状に変形させた状態で鏡面加工することにより、前記治具を外したときに前記側面が凸状となるようにしたポリゴンミラーを備えたポリゴンミラーの光偏向装置を主要な特徴とする。
請求項６記載の発明では、側面がミラー面に加工される正角柱部と、前記正角柱部の底面に形成した円筒部とを備えたポリゴンミラーの加工時に前記円筒部内前記正角柱部と同じ多角形状であるポリゴンミラーの加工治具を主要な特徴とする。
請求項７記載の発明では、側面がミラー面に加工される正角柱部と、前記正角柱部の底面に形成した円筒部とを備えたポリゴンミラーの加工時に、前記側面を変形させるためのポリゴンミラーの加工治具を用いたポリゴンミラーの製造方法であって、前記ポリゴンミラーの加工治具を前記円筒部内に配し、前記加工治具からの押圧力によって前記側面を変形させた状態で鏡面加工し、前記ポリゴンミラーの加工治具を外したときに前記側面が凸状となるようにしたポリゴンミラーの製造方法を主要な特徴とする。
【０００８】
請求項８記載の発明では、前記ポリゴンミラーの加工治具を前記正角柱部と同じ多角形状とし、前記ポリゴンミラーの加工治具の各頂点が向く方向が前記正角柱部の頂点が向く方向と同じになるように前記円筒部内に配し、前記ポリゴンミラーの加工治具からの押圧力によって前記側面を凹状に変形させた状態で鏡面加工するポリゴンミラーの製造方法を主要な特徴とする。
請求項９記載の発明では、前記ポリゴンミラーの加工治具を前記円筒部内へ配したときに前記ポリゴンミラーが位置決めされるようにしたポリゴンミラーの製造方法を主要な特徴とする。
請求項１０記載の発明では、前記正角柱部と前記円筒部を挟んで押圧保持することで前記ポリゴンミラーの加工治具から押圧力を発生させ、該押圧力によって前記側面を凹状に変形させた状態で前記側面の鏡面加工をするようにしたポリゴンミラーの製造方法を主要な特徴とする。
請求項１１記載の発明では、前記正角柱部及び前記円筒部を弾性体を介して押圧保持し、前記ポリゴンミラーの加工治具からの押圧力によって前記側面を凹状に変形させた状態で前記側面の鏡面加工をするようにしたポリゴンミラーの製造方法を主要な特徴とする。
請求項１２記載の発明では、前記弾性体は前記円筒部と略同形状の環状であるポリゴンミラーの製造方法を主要な特徴とする。
請求項１３記載の発明では、側面がミラー面に加工される正角柱部と、前記正角柱部の底面に形成した円筒部とを備えたポリゴンミラーの加工時に、前記側面を変形させるためのポリゴンミラーの加工治具を用いたポリゴンミラーの製造装置であって、前記ポリゴンミラーの加工治具を前記円筒部内に配し、前記ポリゴンミラーの加工治具からの押圧力によって前記側面を変形させた状態で鏡面加工することができ、鏡面加工後に前記ポリゴンミラーの加工治具を外したときに前記側面が凸状となるようにしたポリゴンミラーの製造装置を主要な特徴とする。
【０００９】
請求項１４記載の発明では、前記ポリゴンミラーの加工治具を前記正角柱部と同じ多角形状とし、前記ポリゴンミラーの加工治具の各頂点が向く方向が前記正角柱部の頂点が向く方向と同じになるように前記円筒部内に配し、前記ポリゴンミラーの加工治具からの押圧力によって前記側面を凹状に変形させた状態で鏡面加工することができるポリゴンミラーの製造装置を主要な特徴とする。
請求項１５記載の発明では、前記ポリゴンミラーの加工治具を前記円筒部内へ配したときに前記ポリゴンミラーが位置決めされるようにしたポリゴンミラーの製造装置を主要な特徴とする。
請求項１６記載の発明では、前記正角柱部と前記円筒部を挟んで押圧保持することで前記ポリゴンミラーの加工治具から押圧力を発生させ、該押圧力によって前記側面を凹状に変形させた状態で前記側面の鏡面加工をすることができるポリゴンミラーの製造装置を主要な特徴とする。
請求項１７記載の発明では、前記正角柱部及び前記円筒部を弾性体を介して押圧保持し、前記ポリゴンミラーの加工治具からの押圧力によって前記側面を凹状に変形させた状態で前記側面の鏡面加工をすることができるポリゴンミラーの製造装置を主要な特徴とする。
請求項１８記載の発明では、前記弾性体は前記円筒部と略同形状の環状であるポリゴンミラーの製造装置を主要な特徴とする。
【００１０】
【発明の実施の形態】
以下、図面により本発明の実施の形態を詳細に説明する。図１は本発明に係るポリゴンミラー１００を示す。ポリゴンミラー１００は、回転軸２及びマグネット４とともに回転子６を構成し、画像形成装置等においては図示を略す固定子に対して回転軸２を中心に回転する。
ポリゴンミラー１００は、例えばアルミニウム合金を鍛造して得られる平面視正多角形（ここでは正六角形）金属加工品の側面を凸状に鏡面加工し、回転駆動時にはその遠心力によって変形して平坦になるように６つの側面１００ｂを構成したもので、正六角形の盤状の正角柱部５と、正角柱部５の下面側に形成された円筒状の円筒部３と、正角柱部５の上面側中央に形成された突出部１ａとを有する。突出部１ａの中央で上記正六角形の重心位置には嵌合孔８が設けられ、回転軸２はその嵌合孔８に嵌合されてポリゴンミラー１００に取り付けられる。
また、環状のマグネット４はその外径が円筒部３の内径と略同径の円筒状を呈し、円筒部３の内側に回転軸２と同心となるように固着される。そして、円筒部３内に装着されたマグネット４に対向する位置に所定距離離間させて巻線コイル（図示せず）を配置し、この部分がモータとして機能するように構成される。
ポリゴンミラー１００の側面１００ｂの加工は図２に示すポリゴンミラーの製造装置２００により行われる。ポリゴンミラーの製造装置２００は、加工前のポリゴンミラー１００を保持する保持装置５０と、図１２に示したと同様の研削工具とから概略構成されている。保持装置５０は、角度割出し盤２６と、角度割出し盤ベース４７と、ベース５１と、支持棒４６と、支持板５２と、加工治具４５と、上押え治具４４と、上押え稼動カバー４３と、上押え治具可動部５３とを備える。
角度割出し盤２６は角度割出し盤ベース４７上に設けられ、角度割出し盤ベース４７とともに中心軸を中心に水平面内で回転可能となっている。ベース５１は円環状を呈して中心軸に対して固定され、ボールベアリング５４を介して角度割出し盤２６の外周に設けられている。ベース５１には上記研削工具と干渉しないように複数の支持棒４６が立設され、支持板５２はこれらの支持棒４６に水平姿勢で支持されている。
角度割出し盤２６の上面には凸部５５が設けられ、加工治具４５の底部には凹部５６が設けられ、この凹部５６が凸部５５に係合して位置決めされた状態で加工治具４５は角度割出し盤２６に締結固定されている。図３に拡大して示すように、加工治具４５の加工基準面４５ａは平滑かつ水平に仕上げられており、後述のようにポリゴンミラー１００の基準面である円筒部３の底面３ａが当接されるようになっている。また、加工基準面４５ａの中央部には治具取付穴５７が形成され、ここにはポリゴンミラーの加工治具４８が嵌合されている。ポリゴンミラーの加工治具４８はこの例では正六角形状とされ、その中央には中心孔４８ａが穿設されている。
【００１１】
図２において、上押え治具可動部５３は支持板５２に取り付けられており、平面視長方形状の基板５８の上面中央に支軸４２が設けられ、かつ、この支軸４２と平行するようにガイド軸５９，５９が設けられて構成されている。支軸４２及びガイド軸５９の各上端部には上押え治具支持板４１が取り付けられてその各上端部が連結されている。これにより、上押え治具可動部５３は基板５８と上押え治具支持板４１とにより規定されるストロークの分だけ上下方向に移動可能となっている。
上押え稼動カバー４３は上押え治具可動部５３の基板５８の下面に取り付けられ、上押え治具４４はその上押え稼動カバー４３に取り付けられている。上押え稼動カバー４３はその外側を覆うカバー６０の内部にベアリング（不図示）を備え、上押え治具４４はそのベアリングに保持されることにより中心軸を中心に水平面内で回転可能となっている。上押え治具４４は平面視円形状を呈し、その下部外周縁にはポリゴンミラー１００の円筒部３と略同径の円環状の周壁部６３が形成されている（図２、図３参照）。
【００１２】
ここで、ポリゴンミラーの製造装置２００によるポリゴンミラーの製造方法について説明する。ポリゴンミラーの製造方法では、まず、ポリゴンミラー１００の嵌合孔８に回転軸２を嵌合させる。続いて、回転軸２の下端部がポリゴンミラーの加工治具４８の中心孔４８ａ内に逃げて円筒部３の底面３ａが加工治具４５の加工基準面４５ａに当接するように、ポリゴンミラー１００を加工治具４５上に設置する。
このとき、ポリゴンミラーの加工治具４８は円筒部３の内側に軽圧入されるが、ポリゴンミラーの加工治具４８の正六角形の各頂点の向く方向は正角柱部５の正六角形の頂点の向く方向と同じになるようになされる。つまり、加工治具４８の外周面の形状は、正角柱部５の外面形状と相似形状をなすように構成されている。この軽圧入により、回転軸２の軸心は中心軸に一致するとともに、ポリゴンミラー１００の正六角形の各頂点の方向へ力が作用して側面１００ｂが中央部を中心に凹状に弾性変形する。
次に、上押え治具可動部５３を下方に移動させて上押え治具４４をゆっくりと下降させ、上押え治具４４、上押え稼動カバー４３及び上押え治具可動部５３の自重により、又は荷重を制御しつつ周壁部６３の底面６３ａによって正角柱部５を押圧保持する。この押圧保持により、図４に矢印Ｆ１で示すようにポリゴンミラー１００には円筒部３の部分に上下から押圧力が作用し、この押圧力から矢印Ｆ２で示す力が発生し、矢印Ｆ３で示す力がポリゴンミラー１００の正六角形の各頂点へ誘導されて各側面１００ｂが図５に示すように中央部を中心に凹状に弾性変形する。
そして、この変形状態で角度割出し盤ベース４７、角度割出し盤２６、加工治具４５及び上押え治具４４を中心軸を中心に回転させ、側面１００ｂを上記研削工具に正対させ、側面１００ｂを平坦に鏡面加工する。
【００１３】
側面１００ｂの鏡面加工が終了すると、ポリゴンミラー１００を上下から押圧したまま角度割出し盤２６により割り出された角度（ここでは６０°）だけ回転させて次の側面１００ｂを上記研削工具に正対させ、平坦に鏡面加工する。以降、この手順を順次繰り返して残りの４つの側面１００ｂを鏡面加工し、加工後は上押え治具可動部５３を上方に移動させて上押え治具４４を上昇させる。
上押え治具４４を上昇させてポリゴンミラーの加工治具４８から取り外すと、側面が鏡面加工されたポリゴンミラー１００が得られるが、このポリゴンミラー１００の側面１００ｂはポリゴンミラーの加工治具４８からの取外し時に図６に示すように押圧力が開放されて各側面１００ｂの面形状が平面視で凸状に揃う。したがって、ポリゴンミラー１００では、高速回転駆動時にミラー面形状が遠心力によって変形して図７のように平坦になるので、ポリゴンミラー１００による光の偏向動作において回転ムラ（ジッター）の発生をなくし、縦線ゆらぎ等の画像不良を防止することができる。
また、ポリゴンミラーの製造装置２００及びこれを用いたポリゴンミラーの製造方法では、ポリゴンミラー１００のミラー面である側面１００ｂを平坦に鏡面加工するだけでよいので加工が簡単である。また、この実施の形態では鏡面加工時にポリゴンミラー１００が上下から保持されるので、円筒部３の内側にポリゴンミラーの加工治具４８を圧入してもこの圧入に伴う正角柱部５の反り返り等の変形を防止することができる。
また、ポリゴンミラーの加工治具４８をポリゴンミラー１００と同様の多角形状（六角形状）とし、ポリゴンミラーの加工治具４８の多角形の各頂点が向く方向がポリゴンミラー１００の多角形の各頂点が向く方向と同じになるようにポリゴンミラーの加工治具４８を円筒部３内に配することでポリゴンミラーの加工治具４８の各頂点からの力がポリゴンミラー１００の前記各頂点の方向へ作用するようにしているので、側面１００ｂを簡単に、且つ効率よく凹状に弾性変形させることができる。
さらに、ポリゴンミラーの加工治具４８を円筒部３の内側に軽圧入することによりポリゴンミラー１００の鏡面加工についての位置決めを行うことができるので、圧入と位置決めとを別途に行う必要がなく鏡面加工作業の効率化を図ることができる。
【００１４】
図８はポリゴンミラー１００を備えたポリゴンミラーの光偏向装置６４の概略を示す。ポリゴンミラーの光偏向装置６４では、既に回転軸２が取り付けられたこのポリゴンミラー１００の円筒部３の内側にマグネット４を装着し、このマグネット４が通電が制御される固定子側の巻線コイル（不図示）に対向するように配置してモータを構成し、これにより、高速回転駆動させるものである。したがって、ポリゴンミラー１００の側面１００ｂは高速回転駆動時の遠心力によって変形して平坦になるので、このポリゴンミラー１００を備えたポリゴンミラーの光偏向装置６４ではジッターの発生が抑制されて高品質の画像を得ることができる。
【００１５】
次に、弾性体６５を介してポリゴンミラー１００を押圧保持する場合のポリゴンミラーの製造装置３００及びポリゴンミラーの製造方法について図９を用いて説明する。ポリゴンミラーの製造装置３００はポリゴンミラーの製造装置２００とほぼ同様の構成であるが、弾性体６５を備えた点で異なるものとなっている。したがって、ポリゴンミラーの製造装置２００と同一の部分については同一符号を付し、その詳細な説明は省略する。
ポリゴンミラーの製造装置３００において、まず、平面視で円筒部３と略同形の環状を呈した弾性体６５は円筒部３に重なり合うように正角柱部５上に載置して、上押え治具可動部５３を下方に移動させて上押え治具４４をゆっくりと下降させる。このとき、周壁部６３の底面６３ａが弾性体６５を押圧するようにポリゴンミラー１００の位置と弾性体６５の位置とを微調整し、この調整により円筒部３がポリゴンミラーの加工治具４８に保持されるとポリゴンミラー１００の軸心は中心軸に一致する。
上押え治具４４、上押え稼動カバー４３及び上押え治具可動部５３の自重により、又は荷重を制御されつつ周壁部６３の底面６３ａが弾性体６５を押圧すると、図１０に矢印Ｆ１で示すようにポリゴンミラー１００には円筒部３の部分に上下から押圧力が作用し、この押圧力から矢印Ｆ２で示す力が発生し、矢印Ｆ３で示す力がポリゴンミラー１００の正六角形の各頂点へ誘導されて各側面１００ｂが図５に示すように中央部を中心に弾性変形する。そして、この膨出状態で角度割出し盤ベース４７、角度割出し盤２６、加工治具４５及び上押え治具４４を中心軸を中心に回転させて側面１００ｂを上記研削工具に正対させ、側面１００ｂを平坦に鏡面加工する。
【００１６】
側面１００ｂの鏡面加工が終了すると、ポリゴンミラー１００を上下から押圧したまま角度割出し盤２６により割り出された角度（ここでは６０°）だけ回転させて次の側面１００ｂを上記研削工具に正対させ、平坦に鏡面加工する。以降、この手順を順次繰り返して残りの４つの側面１００ｂを鏡面加工し、加工後は上押え治具可動部５３を上方に移動させて上押え治具４４を上昇させる。上押え治具４４が上昇して押圧から解放されると、側面が鏡面加工されたポリゴンミラー１００が得られるが、このポリゴンミラー１００の側面１００ｂはその押圧力の解放時に図６に示すように側面１００ｂの面形状が平面視で凸状に揃う。
したがって、ポリゴンミラーの製造装置３００及びこれを用いたポリゴンミラーの製造方法では、ポリゴンミラーの製造装置２００を用いた場合と同様の効果を得ることができるとともに、正角柱部５が弾性体６５を介して押圧されるので正角柱部５に直接的に強い押圧力が作用せず、被加工物の損傷を防止することができる。また、弾性体６５は環状であるから、ポリゴンミラー１００に対して押圧力が一様に分布され、ポリゴンミラー１００の異常変形を抑えるとともに保持力を高めることができる。
なお、この実施の形態では、ポリゴンミラー１００の形状は正六角形として説明したが、正六角形に限定されることはない。また、ポリゴンミラーの製造装置３００及びこれを用いたポリゴンミラーの製造方法においては、弾性体６５を治具と別体として設けるのではなく、例えば弾性部材を上押え治具４４の周壁部６３の底面６３ａに固着しておいてもよい。
【００１７】
【発明の効果】
以上説明したように、請求項１〜３によれば、ポリゴンミラーはそのミラー面形状が高速回転駆動時に遠心力によって変形して平坦になるので、このポリゴンミラーによる光の偏向動作において回転ムラ（ジッター）の発生をなくし、縦線ゆらぎ等の画像不良を防止することができる。
請求項４及び５によれば、ポリゴンミラーの側面は高速回転駆動時の遠心力によって変形して平坦になるので、このポリゴンミラーを備えたポリゴンミラーの光偏向装置においてはジッターの発生が抑制されて高品質の画像を得ることができる。
請求項６によれば、ポリゴンミラーの加工治具をポリゴンミラーと同様の多角形状（六角形状）とし、ポリゴンミラーの加工治具の多角形の各頂点が向く方向がポリゴンミラーの多角形の各頂点が向く方向と同じになるようにポリゴンミラーの加工治具を円筒部内に配することでポリゴンミラーの加工治具の各頂点からの力がポリゴンミラーの前記各頂点の方向へ作用するようにしているので、側面を簡単に、且つ効率よく凹状に弾性変形させることができる。
請求項７によれば、ポリゴンミラーのミラー面である側面を平坦に鏡面加工するだけでよいので加工が簡単である。また、ポリゴンミラーの加工治具を円筒部の内側に軽圧入することによりポリゴンミラーの鏡面加工についての位置決めを行うことができるので、圧入と位置決めとを別途に行う必要がなく鏡面加工作業の効率化を図ることができる。
【００１８】
請求項８によれば、ポリゴンミラーの加工治具をポリゴンミラーと同様の多角形状（六角形状）とし、ポリゴンミラーの加工治具の多角形の各頂点が向く方向がポリゴンミラーの多角形の各頂点が向く方向と同じになるようにポリゴンミラーの加工治具を円筒部内に配することでポリゴンミラーの加工治具の各頂点からの力がポリゴンミラーの前記各頂点の方向へ作用するようにしているので、側面を簡単に、且つ効率よく凹状に弾性変形させることができる。
請求項９によれば、ポリゴンミラーの加工治具を円筒部の内側に軽圧入することによりポリゴンミラーの鏡面加工についての位置決めを行うことができるので、圧入と位置決めとを別途に行う必要がなく鏡面加工作業の効率化を図ることができる。
請求項１０によれば、ポリゴンミラーの製造装置及びこれを用いたポリゴンミラーの製造方法では、ポリゴンミラーのミラー面である側面を平坦に鏡面加工するだけでよいので加工が簡単である。また、この実施の形態では鏡面加工時にポリゴンミラーが上下から保持されるので、円筒部の内側にポリゴンミラーの加工治具を圧入してもこの圧入に伴う正角柱部の反り返り等の変形を防止することができる。
請求項１１によれば、正角柱部が弾性体を介して押圧されるので正角柱部に直接的に強い押圧力が作用せず、被加工物の損傷を防止することができる。また、ポリゴンミラーのミラー面である側面を平坦に鏡面加工するだけでよいので加工が簡単である。さらに、ポリゴンミラーの加工治具を円筒部の内側に軽圧入することによりポリゴンミラーの鏡面加工についての位置決めを行うことができるので、圧入と位置決めとを別途に行う必要がなく鏡面加工作業の効率化を図ることができる。
【００１９】
請求項１２によれば、弾性体は環状であるから、ポリゴンミラーに対して押圧力が一様に分布され、ポリゴンミラーの異常変形を抑えるとともに保持力を高めることができる。また、正角柱部が弾性体を介して押圧されるので正角柱部に直接的に強い押圧力が作用せず、被加工物の損傷を防止することができる。また、ポリゴンミラーのミラー面である側面を平坦に鏡面加工するだけでよいので加工が簡単である。さらに、ポリゴンミラーの加工治具を円筒部の内側に軽圧入することによりポリゴンミラーの鏡面加工についての位置決めを行うことができるので、圧入と位置決めとを別途に行う必要がなく鏡面加工作業の効率化を図ることができる。
請求項１３によれば、ポリゴンミラーのミラー面である側面を平坦に鏡面加工するだけでよいので加工が簡単である。また、ポリゴンミラーの加工治具を円筒部の内側に軽圧入することによりポリゴンミラーの鏡面加工についての位置決めを行うことができるので、圧入と位置決めとを別途に行う必要がなく鏡面加工作業の効率化を図ることができる。
請求項１４によれば、ポリゴンミラーの加工治具をポリゴンミラーと同様の多角形状（六角形状）とし、ポリゴンミラーの加工治具の多角形の各頂点が向く方向がポリゴンミラーの多角形の各頂点が向く方向と同じになるようにポリゴンミラーの加工治具を円筒部内に配することでポリゴンミラーの加工治具の各頂点からの力がポリゴンミラーの前記各頂点の方向へ作用するようにしているので、側面を簡単に、且つ効率よく凹状に弾性変形させることができる。
請求項１５によれば、ポリゴンミラーの加工治具を円筒部の内側に軽圧入することによりポリゴンミラーの鏡面加工についての位置決めを行うことができるので、圧入と位置決めとを別途に行う必要がなく鏡面加工作業の効率化を図ることができる。
【００２０】
請求項１６によれば、ポリゴンミラーの製造装置及びこれを用いたポリゴンミラーの製造方法では、ポリゴンミラーのミラー面である側面を平坦に鏡面加工するだけでよいので加工が簡単である。また、この実施の形態では鏡面加工時にポリゴンミラーが上下から保持されるので、円筒部の内側にポリゴンミラーの加工治具を圧入してもこの圧入に伴う正角柱部の反り返り等の変形を防止することができる。
請求項１７によれば、正角柱部が弾性体を介して押圧されるので正角柱部に直接的に強い押圧力が作用せず、被加工物の損傷を防止することができる。また、ポリゴンミラーのミラー面である側面を平坦に鏡面加工するだけでよいので加工が簡単である。さらに、ポリゴンミラーの加工治具を円筒部の内側に軽圧入することによりポリゴンミラーの鏡面加工についての位置決めを行うことができるので、圧入と位置決めとを別途に行う必要がなく鏡面加工作業の効率化を図ることができる。
請求項１８によれば、弾性体は環状であるから、ポリゴンミラーに対して押圧力が一様に分布され、ポリゴンミラーの異常変形を抑えるとともに保持力を高めることができる。また、正角柱部が弾性体を介して押圧されるので正角柱部に直接的に強い押圧力が作用せず、被加工物の損傷を防止することができる。また、ポリゴンミラーのミラー面である側面を平坦に鏡面加工するだけでよいので加工が簡単である。さらに、ポリゴンミラーの加工治具を円筒部の内側に軽圧入することによりポリゴンミラーの鏡面加工についての位置決めを行うことができるので、圧入と位置決めとを別途に行う必要がなく鏡面加工作業の効率化を図ることができる。
【図面の簡単な説明】
【図１】本発明に係るポリゴンミラー１００の斜視図である。
【図２】本発明に係るポリゴンミラーの製造装置２００の正面図である。
【図３】本発明に係るポリゴンミラーの製造装置２００の要部拡大図である。
【図４】ポリゴンミラー１００の押圧時の力の作用を示す図である。
【図５】ポリゴンミラー１００の押圧時の側面の変形を示す図である。
【図６】図５の状態で側面を鏡面加工した後に得られるポリゴンミラー１００を示す図である。
【図７】高速回転駆動による遠心力によって図６のポリゴンミラー１００の側面が変形して平坦になった状態を示す図である。
【図８】ポリゴンミラーの光偏向装置６４の概略を示す図である。
【図９】弾性体６５を介してポリゴンミラー１００を押圧保持するポリゴンミラーの製造装置３００の要部を示す図である。
【図１０】ポリゴンミラーの製造装置３００におけるポリゴンミラー１００の押圧時の力の作用を示す図である。
【図１１】従来のポリゴンミラー１の斜視図である。
【図１２】従来のポリゴンミラーの製造装置１０の断面図である。
【図１３】従来のポリゴンミラーの製造装置１０の要部の拡大図である。
【符号の説明】
１，１００ポリゴンミラー、１ａ突出部、１ｂ，１００ｂ側面、２回転軸、３円筒部、３ａ，６３ａ底面、４マグネット、５正角柱部、６回転子、８嵌合孔、１０，２００，３００ポリゴンミラーの製造装置、１１，５０保持装置、１２研削工具、１９回転防止部材、２０回転操作部、２１保持治具、２１ａ，３０ａテーパー面、２２バイト、２３鍔部、２３ａ下面、２４回転円盤、２５治具ベース、２６角度割出し盤、２７突堤部、２７ａ，３４ａ上面、２８固定シャフト、２９ａネジ溝、３０拡縮部、３１ピン、３１ａ両端部、３３チャック穴、３４基準面当接部、３５，５５凸部、３６，５６凹部、３７貫通孔、３８保護部材、３９長孔、４０側穴、４１上押え治具支持板、４２支軸、４３上押え稼動カバー、４４上押え治具、４５加工治具、４５ａ加工基準面、４６支持棒、４７角度割出し盤ベース、４８ポリゴンミラーの加工治具、４８ａ中心孔、５１ベース、５２支持板、５３上押え治具可動部、５４ボールベアリング、５７治具取付穴、５８基板、５９ガイド軸、６０カバー、６３周壁部、６４ポリゴンミラーの光偏向装置、６５弾性体[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a polygon mirror, a polygon mirror light deflecting device, a polygon mirror processing jig, a polygon mirror manufacturing method, and a polygon mirror manufacturing device related to an image forming apparatus or an image reading apparatus such as a copying machine, a printer, and a facsimile. About.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a polygon mirror (rotating polygon mirror) used in an image forming apparatus or an image reading apparatus, for example, the one shown in FIG. 11 is known. The polygon mirror 1 constitutes a rotor 6 together with the rotating shaft 2 and the magnet 4, and rotates around the rotating shaft 2 with respect to a stator not shown in an image forming apparatus or the like. The polygon mirror 1 is manufactured by, for example, mirror-finishing a metal workpiece (see FIG. 12) obtained by forging an aluminum alloy, as described later, and has a disc-shaped regular polygon in a plan view regular polygon (here, regular hexagon). It has a prism 5, a cylindrical portion 3 formed on the lower surface of the regular prism 5, and a protrusion 1 a formed at the center of the upper surface of the regular prism 5.
A fitting hole 8 is provided at the center of the center of the protruding portion 1 a at the center of gravity of the regular hexagon, and the rotating shaft 2 is fitted into the fitting hole 8 and attached to the polygon mirror 1. The magnet 4 has a cylindrical shape whose outer diameter is substantially the same as the inner diameter of the cylindrical portion 3, and is fixed inside the cylindrical portion 3 so as to be concentric with the rotating shaft 2. A winding coil (not shown) is disposed at a position facing the magnet 4 mounted in the cylindrical portion 3 with a predetermined distance therebetween, and this portion functions as a motor.
The six side surfaces 1b of the regular prism 5 are mirror-finished smooth light reflecting surfaces (mirror surfaces), and the mirror-finish is performed by the processing device 10 shown in FIG. The processing apparatus 10 includes a holding device 11 for holding the polygon mirror 1 before mirror processing, and a grinding tool 12 for grinding the side surface 1b of the polygon mirror 1 before mirror processing held by the holding device 11. The grinding tool 12 is configured by attaching a cutting tool 22 to a rotating disk 24 that rotates in a vertical plane about a tool rotation axis.
[0003]
The holding device 11 includes an angle indexing plate 26, a jig base 25, a fixed shaft 28, a holding jig 21, a rotation preventing member 19, a scaling unit 30, a rotation operation unit 20, and a reference surface contact. And a part 34. The angle indexing plate 26 is rotatable about a rotation axis of the apparatus in a horizontal plane, and a convex portion 35 is formed on an upper surface thereof. At the lower part of the jig base 25, there is provided a concave portion 36 which engages with the convex portion 35. The concave portion 36 engages with the convex portion 35, whereby the jig base 25 is positioned and fixed on the angle indexing plate 26. ing.
In the jig base 25, a ridge portion 27 extending upward is formed, and a through hole 37 is formed in the center of the jig base 25 above the concave portion 36 in a vertical direction. The fixed shaft 28 is fitted into the through hole 37 and protrudes above the jig base 25, and is fitted inside the lower part of the cylindrical holding jig 21. A flange 23 is formed below the holding jig 21, and the lower surface 23 a of the flange 23 abuts on the upper surface 27 a of the ridge 27 to position the holding jig 21 vertically.
Also, the fitting of the fixed shaft 28 and the holding jig 21 causes the axes of both to coincide with the apparatus rotation axis, and the holding jig 21 is positioned in the horizontal direction. The rotation preventing member 19 prevents the holding jig 21 from rotating on the jig base 25, and plays a role of a so-called “rotation stop”.
[0004]
The expansion / contraction section 30 is provided inside the upper part of the holding jig 21 as shown in an enlarged manner in FIG. Although the expanding / contracting portion 30 has a cylindrical shape as a whole, in actuality, a plurality of components having a shape obtained by equally dividing it in the circumferential direction are gathered, and the interval between the respective components changes to change the cylindrical shape. The diameter D1 is enlarged or reduced. A tapered surface 30 a whose diameter continuously increases upward is formed on the upper outer peripheral side of the expanding / contracting portion 30. A tapered surface 21a is formed on the upper inner peripheral side of the holding jig 21 so as to be in contact with the tapered surface 30a. The inner peripheral side of the upper portion of the expanding / contracting portion 30 is formed with a chuck hole 33 for chucking the rotating shaft 2 as will be described later, and the peripheral wall of the chuck hole 33 is made of rubber or the like for preventing the rotating shaft 2 from being damaged. A member 38 is provided.
The rotation operation unit 20 is screwed into a screw groove 29a formed on the outer peripheral surface of the holding jig 21, and moves up and down while rotating along the screw groove 29a. Slots 39 extending vertically are formed in the holding jig 21 so as to be located below the screw groove 29a, and the width of the slot 39 is perpendicular to the paper surface in FIGS. A pin 31 having a diameter substantially the same as that of the pin 31 is fixed so as to extend in the horizontal direction, and both end portions 31 a of the pin 31 project out of the holding jig 21 through the elongated holes 39, 39. ing. Further, the expanding / contracting portion 30 is urged upward by a spring member (not shown), and both ends 31a, 31a of the pin 31 are in contact with the rotary operation portion 20 from below by the urging force.
When the rotation operation unit 20 is rotated and moved downward, the pin 31 moves downward against the urging force, and the expansion / contraction unit 30 descends. At this time, since the tapered surface 30a moves downward while being in sliding contact with the tapered surface 21a, the distance between the constituent members constituting the expansion / contraction section 30 is gradually reduced, and the chuck hole, which is the distance between the opposing constituent members, is reduced. The diameter of 33 (cylinder diameter D1) is reduced.
On the other hand, when the rotation operation unit 20 is rotated and moved upward, the pin 31 follows the rotation operation unit 20 due to the urging force, and the enlargement / reduction unit 30 moves up. At this time, since the tapered surface 30a moves upward while being in sliding contact with the tapered surface 21a, the distance between the constituent members constituting the expansion / contraction section 30 gradually increases, and the diameter of the chuck hole 33 increases.
[0005]
The reference surface contact portion 34 is screwed into the screw groove 29a so as to be located above the rotary operation portion 20. The reference surface contact portion 34 is finely mounted and adjusted so that the upper surface 34a is horizontal, and the bottom surface 3a of the cylindrical portion 3 which is a processing reference surface of the polygon mirror 1 before processing is brought into contact with the upper surface 34a. . The reference surface contact portion 34 is provided with a plurality of side holes 40 along the circumferential direction. A rod-shaped member (not shown) can be inserted into the side holes 40, and the rotating shaft 2 is If the clamping force is weakened by the chuck 30, the clamping force can be increased by the rod-shaped member.
In order to mirror-process the polygon mirror 1 before processing by the processing apparatus 10, first, the rotating shaft 2 and the magnet 4 are attached to the fitting hole 8 and the cylindrical portion 3 of the polygon mirror 1 in FIG. The rotation shaft 2 is chucked by operating the rotation operation unit 20. At this time, the bottom surface 3a of the cylindrical portion 3 is brought into contact with the upper surface 34a of the reference surface contact portion 34 so that the attitude of the polygon mirror 1 is horizontal, and the axis of the rotating shaft 2 coincides with the device rotating axis.
Subsequently, the angle indexing plate 26 is rotated about the rotation axis of the apparatus so that the side surface 1b of the polygon mirror 1 before machining is directly opposed to the rotating disk 24 of the grinding tool 12. Then, after finely adjusting the distance relationship between the side surface 1b and the rotating disk 24, the rotating disk 24 is rotated, and the side surface 1b is ground by the cutting tool 22 while relatively moving the two, so that the side surface 1b is mirror-finished.
Thereafter, the angle indexing plate 26 is rotated while the rotating shaft 2 is being chucked, and all the side surfaces 1b are sequentially faced to the rotating disk 24, and each side surface 1b is mirror-finished in the same procedure as described above. The rotor 6 including the polygon mirror 1 is obtained by operating the unit 20 to release the chuck.
Incidentally, a polygon mirror, a light deflecting device, and the like, which are the above-described conventional techniques, have been proposed (for example, see Patent Documents 1 and 2). In the polygon mirror of Patent Literature 1, deformation of the mirror reflecting surface during rotation is suppressed by providing a reinforcing rib. In the optical deflector of Patent Literature 2, the thickness of the rotating polygon mirror is increased outward in the radial direction. By adopting a tapered shape that gradually increases, deformation of the reflecting surface shape during rotational driving is reduced.
However, in Patent Literature 1, there is a problem in that the provision of a new reinforcing rib causes an increase in the size of the component, and that forming the polygon mirror body and the reinforcing rib integrally complicates the processing. Further, in Patent Document 2, there is a problem that the processing is troublesome because the tapered shape is required.
[Patent Document 1] Japanese Utility Model Laid-Open No. 6-2322
[Patent Document 2] JP-A-2001-4946
[0006]
[Problems to be solved by the invention]
In recent years, demands for higher speed and higher performance (higher image quality) have been strictly demanded for image forming apparatuses and the like, and polygon mirrors used for them have also been required to be able to rotate at high speed and have high accuracy (for example, Regarding the flatness quality (surface accuracy) of the mirror surface of the polygon mirror, the required accuracy has been raised from 4λ / 5 (λ = 0.633 μm) to λ / 5.)
Increasing the speed of the polygon mirror also affects the shape accuracy of the polygon mirror. For example, at a high speed rotation of about 30,000 rpm, the mirror surface end of the polygon mirror expands due to centrifugal force, and the mirror surface becomes concave. The higher the speed, the larger the amount of bulging at the mirror end. If the mirror surface has a concave shape, it becomes impossible to satisfy required performances such as a large beam diameter and a positional shift of a focal length, and rotation unevenness (jitter) occurs, resulting in image defects such as vertical line fluctuation. Therefore, it is important that the mirror surface shape affected by the centrifugal force has a desired flatness during high-speed rotation driving.
To meet such demands, for example, a polygon mirror disclosed in Japanese Utility Model Laid-Open No. 6-2323, an optical deflection device disclosed in Japanese Patent Application Laid-Open No. 2001-4946, and the like have been proposed. In the polygon mirror disclosed in Japanese Unexamined Utility Model Publication No. Hei 6-2332, the deformation of the mirror reflecting surface during rotation is suppressed by providing a reinforcing rib. In the optical deflector disclosed in JP-A-2001-4946, the thickness of the rotating polygon mirror is reduced. The tapered shape gradually increases toward the outside in the radial direction, thereby reducing the deformation of the reflecting surface shape at the time of rotational driving.
However, Japanese Unexamined Utility Model Publication No. 6-2332 has problems in that the provision of a new reinforcing rib causes an increase in the size of the component, and the polygon mirror body and the reinforcing rib are integrally formed to complicate the processing. Also, Japanese Patent Application Laid-Open No. 2001-4946 has a problem that the processing is troublesome because the taper shape is required.
Therefore, the present invention has been made to solve the above-described problems, and uses a polygon mirror and a polygon mirror which are easy to process and which help prevent image defects caused by abnormal shape of the mirror surface of the polygon mirror. It is an object of the present invention to provide a light deflecting device, a polygon mirror processing jig, a polygon mirror manufacturing method, and a polygon mirror manufacturing apparatus.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the invention according to claim 1, in a polygon mirror including a regular prism having a side surface as a mirror surface and a cylindrical portion formed on a bottom surface of the regular prism, The most main feature of the surface is a polygon mirror that is deformed and flattened by centrifugal force during rotational driving.
According to the second aspect of the present invention, the side surface is convex when the jig is removed by performing mirror finishing while deforming the side surface into a concave shape by a pressing force from a jig disposed in the cylindrical portion. The main feature of the present invention is a polygon mirror.
The invention according to claim 3 is characterized mainly by a polygon mirror in which the side surface is mirror-finished while being pressed and held with the regular prism portion and the cylindrical portion interposed therebetween.
According to the fourth aspect of the present invention, there is provided a polygon mirror including a regular prism having a side surface as a mirror surface, and a cylindrical portion formed on the bottom surface of the regular prism, and the mirror surface of the polygon mirror is rotated. The main feature is a polygon mirror optical deflection device which is deformed and flattened by centrifugal force at the time of driving.
In the invention according to claim 5, the side surface is convex when the jig is removed by mirror-finish processing while deforming the side surface into a concave shape by a pressing force from a jig arranged in the cylindrical portion. The main feature of the present invention is a polygon mirror optical deflector provided with a polygon mirror.
In the invention according to claim 6, when processing a polygon mirror including a regular prism portion whose side surface is machined into a mirror surface and a cylindrical portion formed on the bottom surface of the regular prism portion, the same as the regular prism portion in the cylindrical portion when machining a polygon mirror. The main feature is a processing jig for a polygon mirror having a polygonal shape.
In the invention according to claim 7, a polygon for deforming the side surface at the time of processing a polygon mirror having a regular prism portion whose side surface is processed into a mirror surface and a cylindrical portion formed on the bottom surface of the regular prism portion. A method of manufacturing a polygon mirror using a mirror processing jig, wherein the polygon mirror processing jig is disposed in the cylindrical portion, and the side surface is deformed by a pressing force from the processing jig. The main feature is a method for manufacturing a polygon mirror in which the side surface becomes convex when the processing is performed and the processing jig of the polygon mirror is removed.
[0008]
In the invention according to claim 8, the processing jig of the polygon mirror has the same polygonal shape as the regular prism portion, and the direction in which each vertex of the processing jig of the polygon mirror faces is the direction in which the vertex of the regular prism portion faces. The main feature is a method for manufacturing a polygon mirror which is arranged in the cylindrical portion so as to be the same, and mirror-processes the side surface in a concave shape by pressing force from a processing jig of the polygon mirror.
The main feature of the invention according to claim 9 is a method for manufacturing a polygon mirror in which the polygon mirror is positioned when a processing jig for the polygon mirror is arranged in the cylindrical portion.
According to the tenth aspect of the present invention, a pressing force is generated from a processing jig of the polygon mirror by pressing and holding the regular prism portion and the cylindrical portion, and the pressing surface deforms the side surface into a concave shape. The main feature is a method of manufacturing a polygon mirror in which the side surface is mirror-finished in the state.
In the invention according to claim 11, the regular prism portion and the cylindrical portion are pressed and held via an elastic body, and the side surface is deformed into a concave shape by a pressing force from a processing jig of the polygon mirror. The main feature of the present invention is a method of manufacturing a polygon mirror for performing mirror finishing.
According to a twelfth aspect of the present invention, the main feature is a method for manufacturing a polygon mirror in which the elastic body has an annular shape substantially the same as the cylindrical portion.
In the invention according to claim 13, a polygon for deforming the side surface at the time of processing a polygon mirror having a regular prism portion whose side surface is processed into a mirror surface and a cylindrical portion formed on the bottom surface of the regular prism portion. An apparatus for manufacturing a polygon mirror using a mirror processing jig, wherein the polygon mirror processing jig is disposed in the cylindrical portion, and the side surface is deformed by a pressing force from the polygon mirror processing jig. The main feature of the present invention is a polygon mirror manufacturing apparatus in which mirror processing can be performed in a state, and the side surface becomes convex when a processing jig of the polygon mirror is removed after mirror processing.
[0009]
In the invention according to claim 14, the processing jig of the polygon mirror has the same polygonal shape as the regular prism portion, and the direction in which each vertex of the processing jig of the polygon mirror faces is the direction in which the vertex of the regular prism portion faces. The main feature is a polygon mirror manufacturing apparatus which is arranged in the cylindrical portion so as to be the same, and is capable of performing mirror surface processing in a state where the side surface is deformed into a concave shape by a pressing force from a processing jig of the polygon mirror. I do.
According to a fifteenth aspect of the present invention, the main feature is a polygon mirror manufacturing apparatus in which the polygon mirror is positioned when a processing jig for the polygon mirror is arranged in the cylindrical portion.
In the invention according to claim 16, the pressing force is generated from the processing jig of the polygon mirror by pressing and holding the regular prism portion and the cylindrical portion, and the side surface is deformed by the pressing force. The main feature of the present invention is a polygon mirror manufacturing apparatus capable of mirror-finishing the side surface in the state.
In the invention according to claim 17, the regular prism portion and the cylindrical portion are pressed and held via an elastic body, and the side surface is deformed into a concave shape by a pressing force from a processing jig of the polygon mirror. The main feature of the present invention is a polygon mirror manufacturing apparatus capable of performing mirror finishing.
According to an eighteenth aspect of the present invention, the main feature is a device for manufacturing a polygon mirror in which the elastic body has an annular shape substantially the same as the cylindrical portion.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a polygon mirror 100 according to the present invention. The polygon mirror 100 constitutes a rotor 6 together with the rotating shaft 2 and the magnet 4, and rotates around the rotating shaft 2 with respect to a stator not shown in an image forming apparatus or the like.
The polygon mirror 100 is formed by, for example, processing a side view of a metal workpiece having a regular polygonal shape (a regular hexagon in this case) obtained by forging an aluminum alloy into a convex shape, and deforming by centrifugal force during rotation to flatten the surface. The six side surfaces 100b are configured so as to form a regular hexagonal disc-shaped regular prism 5, a cylindrical cylinder 3 formed on the lower surface side of the regular prism 5, and an upper surface of the regular prism 5. And a protruding portion 1a formed at the side center. A fitting hole 8 is provided in the center of the protruding portion 1a at the position of the center of gravity of the regular hexagon, and the rotating shaft 2 is fitted into the fitting hole 8 and attached to the polygon mirror 100.
The annular magnet 4 has a cylindrical shape whose outer diameter is substantially the same as the inner diameter of the cylindrical portion 3, and is fixed inside the cylindrical portion 3 so as to be concentric with the rotating shaft 2. A winding coil (not shown) is disposed at a position facing the magnet 4 mounted in the cylindrical portion 3 with a predetermined distance therebetween, and this portion functions as a motor.
The processing of the side surface 100b of the polygon mirror 100 is performed by the polygon mirror manufacturing apparatus 200 shown in FIG. The polygon mirror manufacturing apparatus 200 is roughly composed of a holding device 50 for holding the polygon mirror 100 before processing, and a grinding tool similar to that shown in FIG. The holding device 50 includes an angle indexing plate 26, an angle indexing plate base 47, a base 51, a support rod 46, a support plate 52, a processing jig 45, an upper holding jig 44, and an upper holding operation. A cover 43 and an upper holding jig movable section 53 are provided.
The angle indexing plate 26 is provided on an angle indexing plate base 47, and is rotatable in a horizontal plane about a central axis together with the angle indexing plate base 47. The base 51 has an annular shape and is fixed to the central axis, and is provided on the outer periphery of the angle indexing plate 26 via a ball bearing 54. A plurality of support rods 46 are erected on the base 51 so as not to interfere with the grinding tool, and the support plate 52 is supported by the support rods 46 in a horizontal posture.
A convex portion 55 is provided on the upper surface of the angle indexing plate 26, and a concave portion 56 is provided on a bottom portion of the processing jig 45. 45 is fastened and fixed to the angle indexing board 26. 3, the processing reference surface 45a of the processing jig 45 is finished smoothly and horizontally, and the bottom surface 3a of the cylindrical portion 3, which is the reference surface of the polygon mirror 100, comes into contact with the processing jig 45 as described later. It is supposed to be. A jig mounting hole 57 is formed at the center of the processing reference surface 45a, and a polygon mirror processing jig 48 is fitted therein. The processing jig 48 of the polygon mirror has a regular hexagonal shape in this example, and a center hole 48a is formed in the center thereof.
[0011]
In FIG. 2, an upper holding jig movable portion 53 is attached to a support plate 52, and a support shaft 42 is provided at the center of the upper surface of a substrate 58 having a rectangular shape in a plan view, and is parallel to the support shaft 42. Guide shafts 59 are provided. The upper holding jig support plate 41 is attached to each upper end of the support shaft 42 and the guide shaft 59, and the upper ends thereof are connected. Thus, the upper holding jig movable section 53 can be moved up and down by a stroke defined by the substrate 58 and the upper holding jig support plate 41.
The upper press operation cover 43 is attached to the lower surface of the substrate 58 of the upper press jig movable section 53, and the upper press jig 44 is attached to the upper press operation cover 43. The upper holding operation cover 43 includes a bearing (not shown) inside the cover 60 that covers the outside thereof, and the upper holding jig 44 is rotatable about a central axis in a horizontal plane by being held by the bearing. I have. The upper holding jig 44 has a circular shape in plan view, and an annular peripheral wall 63 having substantially the same diameter as the cylindrical portion 3 of the polygon mirror 100 is formed on a lower outer peripheral edge thereof (see FIGS. 2 and 3). .
[0012]
Here, a method of manufacturing a polygon mirror by the polygon mirror manufacturing apparatus 200 will be described. In the method of manufacturing the polygon mirror, first, the rotating shaft 2 is fitted into the fitting hole 8 of the polygon mirror 100. Subsequently, the polygon mirror 100 is moved so that the lower end of the rotating shaft 2 escapes into the center hole 48a of the processing jig 48 of the polygon mirror and the bottom surface 3a of the cylindrical portion 3 comes into contact with the processing reference surface 45a of the processing jig 45. Is set on the processing jig 45.
At this time, the processing jig 48 of the polygon mirror is lightly pressed into the inside of the cylindrical portion 3, but the direction of each of the vertices of the regular hexagon of the processing jig 48 of the polygon mirror faces the vertex of the regular hexagon of the regular prism 5. It is made to be the same as the direction to face. That is, the shape of the outer peripheral surface of the processing jig 48 is configured to be similar to the outer surface shape of the regular prism 5. Due to this light press-fitting, the axis of the rotating shaft 2 coincides with the central axis, and a force acts in the direction of each vertex of the regular hexagon of the polygon mirror 100, so that the side surface 100b is elastically deformed concavely around the central portion.
Next, the upper holding jig movable section 53 is moved downward to slowly lower the upper holding jig 44, and the weight of the upper holding jig 44, the upper holding operating cover 43, and the upper holding jig movable section 53 is reduced. Alternatively, the regular prism portion 5 is pressed and held by the bottom surface 63a of the peripheral wall portion 63 while controlling the load. Due to the pressing and holding, a pressing force acts on the polygon mirror 100 from above and below on the cylindrical portion 3 as shown by an arrow F1 in FIG. 4, and a force shown by an arrow F2 is generated from this pressing force and shown by an arrow F3. The force is guided to each vertex of the regular hexagon of the polygon mirror 100, and each side surface 100b is elastically deformed concavely around the central portion as shown in FIG.
Then, in this deformed state, the angle indexing plate base 47, the angle indexing plate 26, the processing jig 45, and the upper holding jig 44 are rotated about the central axis, and the side surface 100b is directly opposed to the grinding tool. 100b is mirror-finished flat.
[0013]
When the mirror surface processing of the side surface 100b is completed, the polygon mirror 100 is rotated by the angle (here, 60 °) determined by the angle indexing plate 26 while pressing the polygon mirror 100 from above and below, so that the next side surface 100b faces the grinding tool. And mirror-finished flat. Thereafter, this procedure is sequentially repeated to mirror-process the remaining four side surfaces 100b. After the processing, the upper holding jig movable section 53 is moved upward to raise the upper holding jig 44.
When the upper holding jig 44 is lifted and removed from the polygon mirror processing jig 48, a polygon mirror 100 having a mirror-finished side surface is obtained. The side surface 100b of the polygon mirror 100 is removed from the polygon mirror processing jig 48. 6, the pressing force is released as shown in FIG. 6, and the surface shape of each side surface 100b becomes convex in plan view. Accordingly, in the polygon mirror 100, the mirror surface shape is deformed by the centrifugal force during the high-speed rotation driving and becomes flat as shown in FIG. 7, so that rotation unevenness (jitter) is eliminated in the light deflection operation by the polygon mirror 100, Image defects such as vertical line fluctuation can be prevented.
Further, in the polygon mirror manufacturing apparatus 200 and the polygon mirror manufacturing method using the same, the mirror surface of the polygon mirror 100 only needs to be flatly mirror-finished, so that the processing is simple. Further, in this embodiment, since the polygon mirror 100 is held from above and below at the time of mirror polishing, even if the processing jig 48 of the polygon mirror is press-fitted inside the cylindrical portion 3, the warping of the regular prism 5 due to this press-fitting is performed. Can be prevented from being deformed.
Also, the processing jig 48 of the polygon mirror has a polygonal shape (hexagonal shape) similar to that of the polygon mirror 100, and each vertex of the polygon of the processing jig 48 of the polygon mirror faces each vertex of the polygon of the polygon mirror 100. Are arranged in the cylindrical portion 3 so that the forces from the vertices of the polygon mirror processing jig 48 are directed in the direction of the vertices of the polygon mirror 100. Since it acts, the side surface 100b can be easily and efficiently elastically deformed into a concave shape.
Further, since the polygon mirror 100 can be positioned for mirror finishing by lightly press-fitting the polygon mirror processing jig 48 into the inside of the cylindrical portion 3, there is no need to perform press-fitting and positioning separately. Work efficiency can be improved.
[0014]
FIG. 8 schematically shows a polygon mirror optical deflector 64 having a polygon mirror 100. In the polygon mirror optical deflector 64, a magnet 4 is mounted inside the cylindrical portion 3 of the polygon mirror 100 on which the rotary shaft 2 is already mounted, and the magnet 4 is controlled by a winding coil on the stator side. The motor is configured to be opposed to (not shown) so that the motor is driven to rotate at high speed. Therefore, since the side surface 100b of the polygon mirror 100 is deformed and flattened by the centrifugal force at the time of high-speed rotation driving, in the polygon mirror optical deflecting device 64 provided with the polygon mirror 100, generation of jitter is suppressed and high quality is achieved. Images can be obtained.
[0015]
Next, a polygon mirror manufacturing apparatus 300 and a polygon mirror manufacturing method when the polygon mirror 100 is pressed and held via the elastic body 65 will be described with reference to FIG. The polygon mirror manufacturing apparatus 300 has substantially the same configuration as the polygon mirror manufacturing apparatus 200, but differs in that an elastic body 65 is provided. Therefore, the same parts as those of the polygon mirror manufacturing apparatus 200 are denoted by the same reference numerals, and detailed description thereof will be omitted.
In the polygon mirror manufacturing apparatus 300, first, an elastic body 65 having an annular shape substantially the same as the cylindrical portion 3 in plan view is placed on the regular prism portion 5 so as to overlap the cylindrical portion 3, and an upper holding jig is provided. The movable part 53 is moved downward to lower the upper holding jig 44 slowly. At this time, the position of the polygon mirror 100 and the position of the elastic body 65 are finely adjusted so that the bottom surface 63a of the peripheral wall portion 63 presses the elastic body 65, and the cylindrical portion 3 is moved to the polygon mirror processing jig 48 by this adjustment. When held, the axis of the polygon mirror 100 coincides with the central axis.
When the bottom surface 63a of the peripheral wall portion 63 presses the elastic body 65 by the own weight of the upper holding jig 44, the upper holding operating cover 43, and the upper holding jig movable portion 53 or while controlling the load, the arrow F1 is shown in FIG. As described above, a pressing force acts on the polygon mirror 100 from above and below on the cylindrical portion 3, and a force indicated by an arrow F2 is generated from the pressing force, and the force indicated by the arrow F3 is applied to each vertex of the regular hexagon of the polygon mirror 100. As a result, each side surface 100b is elastically deformed around the central portion as shown in FIG. Then, in this swelling state, the angle indexing plate base 47, the angle indexing plate 26, the processing jig 45, and the upper holding jig 44 are rotated about the central axis so that the side surface 100b faces the grinding tool, The side surface 100b is mirror-finished flat.
[0016]
When the mirror surface processing of the side surface 100b is completed, the polygon mirror 100 is rotated by the angle (here, 60 °) determined by the angle indexing plate 26 while pressing the polygon mirror 100 from above and below, so that the next side surface 100b faces the grinding tool. And mirror-finished flat. Thereafter, this procedure is sequentially repeated to mirror-process the remaining four side surfaces 100b. After the processing, the upper holding jig movable section 53 is moved upward to raise the upper holding jig 44. When the upper holding jig 44 is lifted and released from the pressing, a polygon mirror 100 having a mirror-finished side surface is obtained. When the pressing force is released, the side surface 100b of the polygon mirror 100 is released as shown in FIG. The surface shape of the side surface 100b becomes uniform in a plan view.
Therefore, in the polygon mirror manufacturing apparatus 300 and the polygon mirror manufacturing method using the same, the same effect as in the case of using the polygon mirror manufacturing apparatus 200 can be obtained, and the regular prism 5 has the elastic body 65. Since the pressing is performed via the intermediate member, a strong pressing force does not directly act on the regular prism portion 5, and damage to the workpiece can be prevented. Further, since the elastic body 65 is annular, the pressing force is uniformly distributed on the polygon mirror 100, so that abnormal deformation of the polygon mirror 100 can be suppressed and the holding force can be increased.
In this embodiment, the shape of the polygon mirror 100 is described as a regular hexagon, but is not limited to a regular hexagon. In the polygon mirror manufacturing apparatus 300 and the polygon mirror manufacturing method using the same, the elastic body 65 is not provided separately from the jig. It may be fixed to the bottom surface 63a.
[0017]
【The invention's effect】
As described above, according to the first to third aspects, the polygon mirror has a mirror surface shape deformed by centrifugal force during high-speed rotation driving and flattened. Jitter) can be prevented, and image defects such as vertical line fluctuation can be prevented.
According to the fourth and fifth aspects, since the side surface of the polygon mirror is deformed and flattened by the centrifugal force at the time of high-speed rotation driving, the occurrence of jitter is suppressed in the optical deflection device of the polygon mirror having the polygon mirror. To obtain high quality images.
According to the sixth aspect, the processing jig of the polygon mirror has a polygonal shape (hexagonal shape) similar to that of the polygon mirror, and each vertex of the polygon of the processing jig of the polygon mirror faces each of the polygons of the polygon mirror. By arranging the processing jig of the polygon mirror in the cylindrical portion so as to be the same as the direction in which the vertices face, the force from each vertex of the processing jig of the polygon mirror acts in the direction of each of the vertices of the polygon mirror. Therefore, the side surface can be easily and efficiently elastically deformed into a concave shape.
According to the seventh aspect, the mirror side of the polygon mirror need only be flatly mirror-finished, so that the processing is simple. In addition, since the polygon mirror can be positioned for mirror finishing by lightly press-fitting the polygon mirror processing jig into the inside of the cylindrical portion, there is no need to separately perform press-fitting and positioning, thereby improving the efficiency of the mirror finishing work. Can be achieved.
[0018]
According to the eighth aspect, the processing jig of the polygon mirror has a polygonal shape (hexagonal shape) similar to that of the polygon mirror, and each vertex of the polygon of the processing jig of the polygon mirror faces each of the polygons of the polygon mirror. By arranging the processing jig of the polygon mirror in the cylindrical portion so as to be the same as the direction in which the vertices face, the force from each vertex of the processing jig of the polygon mirror acts in the direction of each of the vertices of the polygon mirror. Therefore, the side surface can be easily and efficiently elastically deformed into a concave shape.
According to the ninth aspect, by positioning the processing jig of the polygon mirror lightly into the inside of the cylindrical portion, it is possible to perform positioning for mirror surface processing of the polygon mirror, so that it is not necessary to separately perform press-fitting and positioning. It is possible to improve the efficiency of the mirror finishing work.
According to the tenth aspect, in the polygon mirror manufacturing apparatus and the polygon mirror manufacturing method using the same, the mirror mirror surface of the polygon mirror need only be flatly mirror-finished, so that the processing is simple. Further, in this embodiment, since the polygon mirror is held from above and below during the mirror finishing, even if the processing jig of the polygon mirror is pressed into the inside of the cylindrical portion, deformation such as warping of the regular prism portion caused by the press fitting is prevented. can do.
According to the eleventh aspect, since the regular prism is pressed via the elastic body, a strong pressing force does not directly act on the regular prism, and damage to the workpiece can be prevented. Further, the mirror surface of the polygon mirror need only be flatly mirror-finished, so that the processing is simple. Furthermore, since the polygon mirror can be positioned for mirror finishing by lightly press-fitting the polygon mirror processing jig into the inside of the cylindrical portion, there is no need to perform separate press-fitting and positioning, thereby improving the efficiency of the mirror finishing work. Can be achieved.
[0019]
According to the twelfth aspect, since the elastic body is annular, the pressing force is uniformly distributed on the polygon mirror, so that abnormal deformation of the polygon mirror can be suppressed and the holding force can be increased. Further, since the regular prism portion is pressed via the elastic body, a strong pressing force does not directly act on the regular prism portion, and damage to the workpiece can be prevented. Further, the mirror surface of the polygon mirror need only be flatly mirror-finished, so that the processing is simple. Furthermore, since the polygon mirror can be positioned for mirror finishing by lightly press-fitting the polygon mirror processing jig into the inside of the cylindrical portion, there is no need to perform separate press-fitting and positioning, thereby improving the efficiency of the mirror finishing work. Can be achieved.
According to the thirteenth aspect, since the mirror surface of the polygon mirror only needs to be flatly mirror-finished, the processing is simple. In addition, since the polygon mirror processing jig is lightly press-fitted into the inside of the cylindrical portion, positioning for mirror processing of the polygon mirror can be performed. Can be achieved.
According to the fourteenth aspect, the processing jig of the polygon mirror has a polygonal shape (hexagonal shape) similar to that of the polygon mirror, and each vertex of the polygon of the processing jig of the polygon mirror faces each of the polygons of the polygon mirror. By arranging the processing jig of the polygon mirror in the cylindrical portion so as to be in the same direction as the direction of the vertex, the force from each vertex of the processing jig of the polygon mirror acts in the direction of each vertex of the polygon mirror. Therefore, the side surface can be easily and efficiently elastically deformed into a concave shape.
According to the fifteenth aspect, it is possible to perform positioning for mirror surface processing of the polygon mirror by lightly press-fitting a processing jig of the polygon mirror into the inside of the cylindrical portion, so that it is not necessary to separately perform press-fitting and positioning. It is possible to improve the efficiency of the mirror finishing work.
[0020]
According to the sixteenth aspect, in the polygon mirror manufacturing apparatus and the polygon mirror manufacturing method using the same, the mirror surface of the polygon mirror need only be flatly mirror-finished, so that the processing is simple. Further, in this embodiment, since the polygon mirror is held from above and below during the mirror finishing, even if the processing jig of the polygon mirror is pressed into the inside of the cylindrical portion, deformation such as warping of the regular prism portion caused by the press fitting is prevented. can do.
According to the seventeenth aspect, since the regular prism portion is pressed via the elastic body, a strong pressing force does not directly act on the regular prism portion, and damage to the workpiece can be prevented. Further, the mirror surface of the polygon mirror need only be flatly mirror-finished, so that the processing is simple. Furthermore, since the polygon mirror can be positioned for mirror finishing by lightly press-fitting the polygon mirror processing jig into the inside of the cylindrical portion, there is no need to perform separate press-fitting and positioning, thereby improving the efficiency of the mirror finishing work. Can be achieved.
According to the eighteenth aspect, since the elastic body is annular, the pressing force is uniformly distributed on the polygon mirror, so that abnormal deformation of the polygon mirror can be suppressed and the holding force can be increased. Further, since the regular prism portion is pressed via the elastic body, a strong pressing force does not directly act on the regular prism portion, and damage to the workpiece can be prevented. Further, the mirror surface of the polygon mirror need only be flatly mirror-finished, so that the processing is simple. Furthermore, since the polygon mirror can be positioned for mirror finishing by lightly press-fitting the polygon mirror processing jig into the inside of the cylindrical portion, there is no need to perform separate press-fitting and positioning, thereby improving the efficiency of the mirror finishing work. Can be achieved.
[Brief description of the drawings]
FIG. 1 is a perspective view of a polygon mirror 100 according to the present invention.
FIG. 2 is a front view of a polygon mirror manufacturing apparatus 200 according to the present invention.
FIG. 3 is an enlarged view of a main part of a polygon mirror manufacturing apparatus 200 according to the present invention.
FIG. 4 is a diagram showing the action of a force when the polygon mirror 100 is pressed.
FIG. 5 is a diagram illustrating deformation of a side surface when the polygon mirror 100 is pressed.
FIG. 6 is a diagram showing a polygon mirror 100 obtained after the side surface is mirror-finished in the state of FIG. 5;
FIG. 7 is a diagram showing a state in which the side surface of the polygon mirror 100 of FIG. 6 is deformed and flattened by centrifugal force generated by high-speed rotation drive.
FIG. 8 is a diagram schematically illustrating a light deflecting device 64 of a polygon mirror.
FIG. 9 is a diagram showing a main part of a polygon mirror manufacturing apparatus 300 that presses and holds the polygon mirror 100 via an elastic body 65.
FIG. 10 is a diagram illustrating the action of a force when the polygon mirror 100 is pressed in the polygon mirror manufacturing apparatus 300.
FIG. 11 is a perspective view of a conventional polygon mirror 1;
FIG. 12 is a cross-sectional view of a conventional polygon mirror manufacturing apparatus 10.
FIG. 13 is an enlarged view of a main part of a conventional polygon mirror manufacturing apparatus 10.
[Explanation of symbols]
1,100 polygon mirror, 1a protrusion, 1b, 100b side, 2 rotation axis, 3 cylinder, 3a, 63a bottom, 4 magnet, 5 regular prism, 6 rotor, 8 fitting hole, 10, 200, 300 Polygon mirror manufacturing device, 11, 50 holding device, 12 grinding tool, 19 rotation prevention member, 20 rotation operation unit, 21 holding jig, 21a, 30a tapered surface, 22 bytes, 23 flange portion, 23a bottom surface, 24 rotating disk , 25 jig base, 26 angle indexer, 27 pier, 27a, 34a upper surface, 28 fixed shaft, 29a screw groove, 30 expanding and contracting part, 31 pin, 31a both ends, 33 chuck hole, 34 reference plane contact part , 35,55 convex portion, 36,56 concave portion, 37 through hole, 38 protective member, 39 long hole, 40 side hole, 41 upper holding jig support plate, 42 support shaft, 43 upper holding operating cover -, 44 Upper holding jig, 45 Processing jig, 45a Processing reference plane, 46 support rod, 47 Angle indexer base, 48 Polygon mirror processing jig, 48a Center hole, 51 base, 52 support plate, 53 Upper Pressing jig movable part, 54 ball bearing, 57 jig mounting hole, 58 substrate, 59 guide shaft, 60 cover, 63 peripheral wall, 64 polygon mirror light deflecting device, 65 elastic body

Claims

In a polygon mirror including a regular prism having a side surface as a mirror surface, and a cylindrical portion formed on a bottom surface of the regular prism,
A polygon mirror, wherein said mirror surface is configured to be deformed and flattened by centrifugal force during rotational driving.

The side surface is mirror-finished in a state where the side surface is concavely deformed by the pressing force from the jig disposed in the cylindrical portion, so that the side surface becomes convex when the jig is removed. 2. The polygon mirror according to claim 1, wherein:

The polygon mirror according to claim 2, wherein the side surface is mirror-finished while being pressed and held with the regular prism portion and the cylindrical portion interposed therebetween.

The polygon mirror includes a regular prism having a side surface as a mirror surface, and a cylindrical portion formed on the bottom surface of the regular prism. The mirror surface of the polygon mirror is deformed by centrifugal force during rotational driving. An optical deflecting device for a polygon mirror, which is configured to be flat.

By pressing the side surface into a concave shape by pressing force from a jig disposed in the cylindrical portion and performing mirror finishing, a polygon mirror in which the side surface becomes convex when the jig is removed is provided. 5. The light deflecting device for a polygon mirror according to claim 4, further comprising:

A polygon for arranging inside the cylindrical portion at the time of processing of a polygon mirror having a regular prism portion whose side surface is processed into a mirror surface and a cylindrical portion formed on the bottom surface of the regular prism portion, and deforming the side surface into a concave shape A mirror processing jig,
A processing jig for a polygon mirror, wherein an outer peripheral surface of the processing jig has a polygonal shape similar to the regular prism portion.

When processing a polygon mirror having a regular prism portion whose side surface is processed into a mirror surface and a cylindrical portion formed on the bottom surface of the regular prism portion, a polygon mirror processing jig for deforming the side surface was used. A method of manufacturing a polygon mirror,
The processing jig of the polygon mirror is disposed in the cylindrical portion, and the side surface is deformed by pressing force from the processing jig, and the surface is deformed. When the processing jig of the polygon mirror is removed, the side surface is removed. Is a convex shape.

The outer peripheral surface of the processing jig of the polygon mirror has a polygonal shape similar to the regular prism portion, and the direction of each vertex of the processing jig of the polygon mirror is the same as the direction of the vertex of the regular prism portion. 8. The method according to claim 7, wherein the polygon mirror is mirror-finished in a state where the side surface is concavely deformed by a pressing force from a processing jig of the polygon mirror.

9. The method according to claim 7, wherein the polygon mirror is positioned when a processing jig for the polygon mirror is disposed in the cylindrical portion.

A pressing force is generated from a processing jig of the polygon mirror by pressing and holding the regular prism portion and the cylindrical portion, and the mirror processing of the side surface is performed in a state where the side surface is deformed into a concave shape by the pressing force. The method for manufacturing a polygon mirror according to any one of claims 7 to 9, wherein:

The regular prism portion and the cylindrical portion are pressed and held via an elastic body, and the side surface is mirror-finished while the side surface is deformed into a concave shape by a pressing force from a processing jig of the polygon mirror. The method for manufacturing a polygon mirror according to any one of claims 7 to 9, wherein:

The method for manufacturing a polygon mirror according to claim 11, wherein the elastic body has an annular shape having substantially the same shape as the cylindrical portion.

When processing a polygon mirror having a regular prism portion whose side surface is processed into a mirror surface and a cylindrical portion formed on the bottom surface of the regular prism portion, a polygon mirror processing jig for deforming the side surface was used. A polygon mirror manufacturing device,
A processing jig for the polygon mirror is disposed in the cylindrical portion, and the side surface is deformed by a pressing force from the processing jig for the polygon mirror. An apparatus for manufacturing a polygon mirror, wherein the side surface becomes convex when a jig is removed.

The outer peripheral surface of the processing jig of the polygon mirror has a polygonal shape similar to the regular prism portion, and the direction of each vertex of the processing jig of the polygon mirror is the same as the direction of the vertex of the regular prism portion. 14. The polygon mirror according to claim 13, wherein the side surface is concavely deformed by the pressing force of the polygon mirror from a processing jig. apparatus.

15. The polygon mirror manufacturing apparatus according to claim 13, wherein the polygon mirror is positioned when a processing jig of the polygon mirror is arranged in the cylindrical portion.

A pressing force is generated from a processing jig of the polygon mirror by pressing and holding the regular prism portion and the cylindrical portion, and the mirror processing of the side surface is performed in a state where the side surface is deformed into a concave shape by the pressing force. The apparatus for manufacturing a polygon mirror according to any one of claims 13 to 15, wherein the apparatus is capable of performing the following.

The regular prism portion and the cylindrical portion can be pressed and held via an elastic body, and the side surface can be mirror-finished in a state where the side surface is deformed into a concave shape by a pressing force from a processing jig of the polygon mirror. The polygon mirror manufacturing apparatus according to any one of claims 13 to 15, wherein:

18. The polygon mirror manufacturing apparatus according to claim 17, wherein the elastic body has an annular shape having substantially the same shape as the cylindrical portion.